In the spring of 2009 Gabe Handy, a commercial developer in Colchester, Vt., explored the benefits of having a solar domestic hot water system for one of his commercial buildings in Vermont. Gabe had been introduced to the idea of solar by the company that services his laundry facilities. In addition to washing machines, they were now carrying solar hot water equipment. Gabe learned of the financing options and state incentives available and wanted to give solar a try.
Gabe decided the property that would gain the most benefit from the thermal installation was the Days Inn, Colchester, Vt. The supply company contacted several installers and made the decision to work with Ray Montana and Greg Dorsey of Maine Energy Performance Solutions.
MEPS, worked closely with the solar equipment manufacturer to design a system to meet the needs of the busy hotel. The materials used were 20 commercial flat plate thermal panels, 4 commercial 119 gallon storage tanks and a large, commercial pump station with built in controls. Excess heat produced by the system was routed to heat the indoor pool. The thermal installation was a major success. A comparison of previous energy bills to the new ones showed that the system actually paid for itself in the first year of operation.
A year later Gabe called MEPS back to discuss the addition of photovoltaic panels to the remaining roof area. MEPS was delighted at the opportunity to have their team be part of Gabe’s next phase of energy conservation. In the course of working out the contract for the project, they learned that snow sliding off the thermal panels and into the parking lot below had created a safety issue for the hotel. MEPS wanted to resolve this issue for the existing system and address it in the proposed new system as well.
Including a resolution to the snow issue in their proposal helped MEPS get the job. In addition to the snow guard plan for both the thermal and PV panels MEPS included a lightning protection component and a new monitoring system for the hot water collectors. With these additions, Gabe was ready to go ahead with the project.
After receiving the report from the structural engineer who was checking the roof capacity, MEPS found some changes to the panel configuration would be necessary. Ray and Greg selected EcoFasten Solar as the supplier for the snow retention solution. “The team at EcoFasten Solar was very knowledgeable in calculating the details for snow loading on this project and provided a plan to meet the engineer’s requirements” said Ray. It was also an added bonus that their manufacturing facility was only an hour from the job site. Ray continues… “We saved the shipping costs by picking up the materials ourselves. We met the crew and had a tour of their facility. EcoFasten Solar even sent someone out the next day to view our job in progress and see how things were going.”
As the hotel’s roof was due for replacement, Ray and Greg knew it made good sense to address that first. They discussed the options with Gabe and the PV system was installed on a brand new asphalt roof replaced specifically for the job. The solar crew, roofers and painters who were also working, were able to share use of staging and lift equipment, as well.
The overall installation took about three weeks. Having the EcoFasten system installed at the same time as the panels worked very well. The snow guards have a patented flashing system that is waterproof without requiring messy caulk. The MEPS team was very pleased with how quick and easy it was to install.
Another innovation on this job was the use of micro-inverters to convert the DC current produced by the panels into AC power that is used in the grid. Typical PV systems use large inverters mounted in the utility room to convert power but the Enphase micro-inverters used in this case were mounted on the roof under the PV panels. Using this approach actually increases the systems efficiency so more power is produced.
In addition to increasing efficiency, the Enphase inverters allow each panel to be monitored individually on the internet. The output from both the PV system and the previously installed thermal system can now be viewed in the lobby of the Days Inn so customers can fully appreciate the advantages of the solar collectors on the roof.
Gabe was smart to act when he did and these two systems got substantial funding through both the federal and Vermont incentive programs. In addition every kilowatt-hour of energy produced by the PV panels earns $0.06 from Green Mountain Power. Even with snow cover and low winter sun angles the system had already produced 1065 kWh of energy between start up in mid-November and the end of December, 2010. Production in the summer will be much higher.
If you want to know how much higher, production and historical data for these systems can be viewed at www.mepsenergy.com.